memset.S revision 5f7ccea3ffab05aeceecb85c821003cf580630d3
1/* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <machine/cpu-features.h> 30#include <machine/asm.h> 31#include "libc_events.h" 32 33/* 34 * This code assumes it is running on a processor that supports all arm v7 35 * instructions, that supports neon instructions, and that supports 36 * unaligned neon instruction accesses to memory. 37 */ 38 39 .fpu neon 40 41ENTRY(__memset_chk) 42 .cfi_startproc 43 cmp r2, r3 44 bls .L_done 45 46 // Preserve lr for backtrace. 47 .save {lr} 48 push {lr} 49 .cfi_def_cfa_offset 4 50 .cfi_rel_offset lr, 0 51 52 ldr r0, error_message 53 ldr r1, error_code 541: 55 add r0, pc 56 bl __fortify_chk_fail 57error_code: 58 .word BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW 59error_message: 60 .word error_string-(1b+8) 61 62 .cfi_endproc 63END(__memset_chk) 64 65ENTRY(bzero) 66 .cfi_startproc 67 mov r2, r1 68 mov r1, #0 69 70.L_done: 71 // Fall through to memset... 72 .cfi_endproc 73END(bzero) 74 75/* memset() returns its first argument. */ 76ENTRY(memset) 77 .cfi_startproc 78 .save {r0} 79 stmfd sp!, {r0} 80 .cfi_def_cfa_offset 4 81 .cfi_rel_offset r0, 0 82 83 vdup.8 q0, r1 84 85 /* make sure we have at least 32 bytes to write */ 86 subs r2, r2, #32 87 blo 2f 88 vmov q1, q0 89 901: /* The main loop writes 32 bytes at a time */ 91 subs r2, r2, #32 92 vst1.8 {d0 - d3}, [r0]! 93 bhs 1b 94 952: /* less than 32 left */ 96 add r2, r2, #32 97 tst r2, #0x10 98 beq 3f 99 100 // writes 16 bytes, 128-bits aligned 101 vst1.8 {d0, d1}, [r0]! 1023: /* write up to 15-bytes (count in r2) */ 103 movs ip, r2, lsl #29 104 bcc 1f 105 vst1.8 {d0}, [r0]! 1061: bge 2f 107 vst1.32 {d0[0]}, [r0]! 1082: movs ip, r2, lsl #31 109 strmib r1, [r0], #1 110 strcsb r1, [r0], #1 111 strcsb r1, [r0], #1 112 ldmfd sp!, {r0} 113 bx lr 114 .cfi_endproc 115END(memset) 116 117 .data 118error_string: 119 .string "memset buffer overflow" 120